Hi Gn, and welcome.
Those Hitachi routers are real workhorses - I have had the baby brother for about 40 years (DIY use), am starting to think about changing the bearings.
1. Most of what you are missing may not be needed, if you stick to the table-mount mode (btw, the guy seems to have quite a nifty idea, using euro hinges to allow lifting the router up for bit changes). The pole you mentioned is need only for setting depth of plunge in hand-held mode, and you can improvise there - it is not that accurate. You are better off using a drill bit of the required diameter, to set the gap between the pole and the one of the stops on the rotating turret below. The machine screws are missing from the stops of the turret - no big deal, not needed for table-mount use, any suitable bolt with a nut threaded on it (to lock a depth setting) will do. Just allows you to reach a desired depth of cut in several passes.
2. The rods and side fence are available as after-market parts, probably better than the original, which was somewhat basic.. only needed for edge routing. There is another piece with a little bearing, used for routing curved edges, if you are into that sort of thing.
3. You have the 1/2” collet with a sleeve to reduce to 1/4” (there were also options for 3/8”). Collet on left, sleeve on right in your image. I second Tom- get another while you can. You may even be able to get a 1/4” collet, which does not require a sleeve. In any case, get another sleeve, they eventually need replacement.
4. That black rubber or plastic disk under the base (called the sub-base) does not look original to me - it probably won’t glide smoothly over wood if the machine is handheld, and the fixing bolts are standing a little proud. No big deal, if you cannot get an original replacement, you can make a perfectly serviceable one out of polycarbonate, and even better, extend it to one side as an offset base for better control, as suggested by Charles.
5. Get some spare motor brushes - the Hitachis have odd sizes. If you cannot find any, you may have to file down slightly larger OEM brushes.
6. The Hitachi bushing guides were not that wonderful in terms of concentricity, but if you want to get into template guided routing (and you should want to, in due course), you can either use bits with bearings on them (easy), or get or make the carrier for commonly-used bushings (like Porter-Cable, which until recently seemed to be the de facto standard in North America). You will see it in the manual as a small flat metal plate with two side holes for bolts to lock it into the base from below, and a large central opening into which different sizes of bushing can be installed (with a locking ring, supplied with a set of bushings). There may even be an after-market type available in your part of the world.
Happy routing - you will wonder how you managed without one up to now.
Last edited by Biagio; 07-25-2019 at 08:08 AM.